APOE ε4 lowers age at onset and is a high risk factor for Alzheimer's disease; A case control study from central Norway

Table 3 Odds Ratio for AD in all genotypes in patients with/without first degree relatives with dementia

	Genotypes
	ε2/ε2	ε2/ε3	ε2/ε4	ε3/ε3	ε3/ε4	ε4/ε4
Odds Ratio (376 AD patients; 561 control individuals)	0.7	0.9	3.2	1	4.2	12.9
CI	0.01–7.57	0.51–1.41	1.67–6.18	Ref	2.98–5.89	6.64–26.68
p value	1.00	0.62	< 0.001		< 0.001	< 0.001
Odds Ratio, AD patients with no family history of dementia (n = 149)	1.1*	0.7	2.8	1	2.9	8.1
CI	0.00–0.16	0.34–1.47	1.17–6.44	Ref	1.83–4.58	3.53–19.18
p value	1.00	0.47	0.021		< 0.001	< 0.000
Odds Ratio, AD patients with first degree relative with dementia (n = 213)	1.7	1.0	4.0	1	5.9	18.7
CI	0.03–17.27	0.47–1.89	1.79–8.86	Ref	3.88–9.15	8.97–41.40
p value	1.0	1.0	< 0.001		< 0.001	< 0.001

SD = Standard Deviation
CI = 95% confidence interval
Ref = Reference category
*The Median unbiased estimate is given, since the Maximum Likelihood estimate does not exist.